The average radial velocity of galaxies in the Hercules cluster is 10,800 km/s. (a) using H0 = 73 km/s/Mpc, find the distance to the Hercules cluster in Mpc. (b) How would your answer to (a) differ if the Hubble constant had a smaller value?

a) 147.95 Mpc

Explanation:

Using Hubble's formula

where;

v = radical velocity

= Hubble's constant

d = distance

Given that:

The average radial velocity of galaxies in the Hercules cluster v =  10,800 km/s

Also using = 73 km/s/ Mpc ; we  make distance d the subject of the formula:

Then distance d can be written as:

d = 147.95 Mpc

b)

Now, if the Hubble constant had a smaller value, then for a  given velocity the distance to the galaxy will increase because distance d is inversely proportional to

i.e  

d  ∝

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s